The compound N-(fluorosulfonyl) dimethylamine (FSO2NMe2) has been proposed as a solvent or additive for lithium-ion batteries (Chinese Patent No. CN 1 289 765A) At present, FSO2NMe2 is not commercially available in large amounts.
FSO2NMe2 was first prepared in the 1930s by metathesis between N-chlorosulfonyl dimethylamine (ClSO2NMe2) and potassium, sodium, or zinc fluoride in water (French Patent No. FR 806 383; German Patent No. DE 667 544; U.S. Pat. No. 2,130,038).
FSO2NMe2 has also been prepared by the reaction of ClSO2NMe2 with antimony trifluoride (SbF3) in the presence of antimony pentafluoride (SbF5) (Heap, R., Saunders, B. C., Journal of the Chemical Society (Resumed), 1948, 1313-1316), and by the reaction of ClSO2NMe2 with anhydrous HF at 80-90° C. (German Patent No. DE 1 943 233 (1971)).
FSO2NMe2 has also been prepared by the reaction of N,N-dimethylaminosulfamide (Me2NSO2NH2) with fluorosulfonyl isocyanate (FSO2N═C═O) at 80° C. (Appel, R.; Montenarh, M., Chemische Berichte, 1977, 110, 2368-2373).
There are four known examples of the reaction of sulfuryl fluoride (SO2F2) with secondary amines as described below. The four known reactions employ cryogens (or catalysts). But the reaction of dimethylamine (Me2NH) with SO2F2 is not known yet.
The reaction of SO2F2 with a secondary amine was first performed in 1948 (Emeléus, H. J., Wood, J. F., Journal of the Chemical Society (Resumed), 1948, 2183-2188). In this paper, diethylamine (Et2NH) was dropped into a cooled (−78° C.) solution of SO2F2 in ethyl ether, and the product, FSO2NEt2, was obtained in a yield of 35%.
The reaction of SO2F2 with piperidine (HN(CH2)5) was performed in 1982 (Padma, D. K., Subrahmanya Bhat, V., Vasudeva Murthy, A. R., Journal of Fluorine Chemistry, 1982, 20, 425-437). SO2F2 was added into piperidine in ether at liquid nitrogen temperatures, followed by warming. Either FSO2N(CH2)5 or SO2(N(CH2)5)2 was obtained depending on the amount of piperidine used.
The reaction of two more secondary amines with SO2F2, under ambient conditions, is described in a patent application by Dong and Sharpless (International Patent Application No. WO 2015/188120). In this application, diallyl amine and dipropargyl amine react with SO2F2 in the presence of an equivalent of an activating agent in a solvent. The solvents such as tetrahyrofuran (THF) and dichloromethane were particularly described (page 58, line 15). Dong and Sharpless asserted that “activated amines can even react in buffer at pH 8” (page 95, line 14), but gave no examples of activated amines, and did not further elaborate.
There is a need for a process for synthesis of N-(fluorosulfonyl) dimethylamine, which is safely and economically scaled up for commercial production.